The crew of the Arctic Sunrise in Greenland. The Arctic Sunrise reached 'the ice bridge' in the Robeson channel, at 82.4 North, near the border between Greenland and Canada.

For the past two weeks, scientists and crew from the Arctic Sunrise have been busy gathering data, collecting samples and setting up cameras to record the break-up of the Petermann glacier, one of Greenland's largest. A large crack has been forming for the past few years, and a massive piece of the glacier is expected to break off soon.

50 cubic meters per second

At 82 degrees North, far from any inhabited area, the impact we have on our environment is sadly evident. The data gathered so far by the on-board scientists is grim. 27 kilometers away from the sea, on the glacier, a large river has formed. The scientists estimate it runs at 50 cubic meters per second - you could fill an Olympic-sized swimming pool in less than a minute at that rate. This river feeds a large and deep melting whirlpool. Measurements there have shown that at around 60 meters depth, the salinity of the water rises - indicating that warm ocean currents from further south in the Atlantic are accelerating the ice melt at a rate much faster than on the surface.

Last year, a 37 kilometer square ice island broke off. This year, the far end of the glacier has already broken away, but much more is expected.

When this new ice island escapes and slips out to sea, it means that more of the 'grounded' or land-based part of the glacier could slip into the sea water and become part of the floating tongue - the end of the glacier that lies on the sea. This has implications for both global sea level rise, as well for the Greenland ice sheet itself, best explained by the 'champagne cork' analogy- if the deterioration of Greenland's glaciers continues, it could open the way for a larger release of frozen fresh water, from the vast ice sheet that covers most of Greenland, into the ocean - thereby contributing to a major rise in sea levels.

Unique environment

Polar bears, seals, icebergs, are all marks of a unique environment endangered by unchecked greenhouse gas emissions. As climate conditions change in the North, it also means life gets a lot harder for the local Inuit population. Their lifestyle and food sources are extremely dependent on the presence of ice. As the species they normally hunt migrate further North, they cannot hunt anymore. The Arctic environment is extremely sensitive to changes.

Ice free Arctic

Bad news is coming from other sources as well. A recent NASA study has shown that the ice cap is not only getting smaller, it's getting thinner and younger. Sea ice has dramatically thinned between 2004 and 2008. Old ice (over 2 years old) takes longer to melt, and is also much harder to replace. As permanent ice decreases, we are looking at ice-free summers in the Arctic as early as 2030.

They say you can't be too thin or too young, but this unfortunately doesn't apply to the Arctic sea ice. Polar bears are the first to suffer from it, but many other species could be affected as well.

Action, not words

World leaders have committed to limit global temperature rise below 2 degrees at the recent G8 meeting, but have not indicated how we will achieve this. Strong emission cuts are needed if we want to prevent runaway global warming.

UPDATE August 20, 2009: The phrase "ice-free summers" in the article above was cited innaccurately on BBC's HardTalk as suggesting the complete loss of land ice as well as sea ice from the Arctic. The phrase is used, exactly as it is in the NASA report from which it is taken, to refer to ice-free waters. Click here for further clarification.